Merge pull request #435 from cds-hooks/non-substantive-ballot-changes

Non substantive ballot changes.

Fixes #238: Clarified how prefetch templates are processed
Fixes #239: Clarified prefetch data conformance language
Fixes #242: Added definition for prefetch key
Fixes #244: Updated conformance language usage in prefetch restrictions
Fixes #246: Clarified prefetch limitations are on prefetch templates
Fixes #257: Added clarification on responses and notes about multiple services from the same hook
Fixes #262: Added examples for each action type
Fixes #264: Clarified documentation for actions
Fixes #274: Clarified hook context table is an example
Fixes #281: Clarified prefetch response resources may be a searchset bundle
Fixes #282: Provided rationale for the use of null in the prefetch response
Fixes #287: Clarified allowable data types for context fields
Fixes #289: Changed prefetch token status change to Major
Fixes #298: Added examples to hook/prefetch discussion
Fixes #300: Added an overview section discussing CDS Hooks components
Fixes #313: Clarified definitions of prefetch template, prefetch token, and prefetch key
Fixes #314: Clarified prefetch behavior for multiple services attached to the same hook
Fixes #316: Added rationale for not allowing next page links in prefetch data
Fixes #344: Clarified distinction between context and prefetch
Fixes #343: Updated prefetch example to use full key names
Fixes #349: Corrected capitalization of conformance language in prefetch description

Author: kpshek